#pragma once

#include <etcd/Client.hpp>
#include <etcd/KeepAlive.hpp>
#include <etcd/Response.hpp>
#include <etcd/Watcher.hpp>
#include <etcd/Value.hpp>
#include "logger.hpp"
#include <thread>

// 服务注册客户端类 
class Registry {
public:
    using ptr = std::shared_ptr<Registry>; 
    Registry(const std::string &host) 
        : _client(std::make_shared<etcd::Client>(host)),
          _keep_alive(_client->leasekeepalive(3).get()),
          _lease_id(_keep_alive->Lease())
    {}
    ~Registry() { _keep_alive->Cancel(); }

    bool registry(const std::string &key, const std::string &val) {
        etcd::Response resp = _client->put(key, val, _lease_id).get();
        if (resp.is_ok() == false) {
            LOG_ERROR("注册数据失败: {}", resp.error_message());
            return false;
        }
        return true;
    }
private: 
    std::shared_ptr<etcd::Client> _client;
    std::shared_ptr<etcd::KeepAlive> _keep_alive;
    uint64_t _lease_id;
};

// 服务发现客户端
class Discovery {
public:
    using ptr = std::shared_ptr<Discovery>; 
    using NotifyCallback = std::function<void(std::string, std::string)>;
    Discovery(const std::string &host, const std::string &basedir, const NotifyCallback &put_cb, const NotifyCallback &del_cb) 
        : _client(std::make_shared<etcd::Client>(host)),
          _put_cb(put_cb), _del_cb(del_cb)
    {
        // 先进行服务发现，先获取到当前已有的数据 
        auto resp = _client->ls(basedir).get();
        if (resp.is_ok() == false) {
            LOG_ERROR("获取服务信息数据失败: {}", resp.error_message());
        }
        int sz = resp.keys().size();
        for (int i = 0; i < sz; i++) {
            std::cout << resp.value(i).as_string() << "可以提供" << resp.key(i) << "服务\n";
            if (_put_cb) _put_cb(resp.key(i), resp.value(i).as_string());
        }
        // 然后进行事件监控，监控数据发生的改变并调用回调进行处理
        _watcher = std::make_shared<etcd::Watcher>(*_client.get(), basedir, std::bind(&Discovery::callback, this, std::placeholders::_1), true);
    }

private:    
    void callback(const etcd::Response &resp) {
        if (resp.is_ok() == false) {
            LOG_ERROR("收到一个错误的事件通知: {}", resp.error_message());
            return ;
        }
        for (auto const &ev : resp.events()) {
            if (ev.event_type() == etcd::Event::EventType::PUT) {
                if (_put_cb) _put_cb(ev.kv().key(), ev.kv().as_string());
                LOG_DEBUG("新增服务: {}-{}", ev.kv().key(), ev.kv().as_string());
            } else if (ev.event_type() == etcd::Event::EventType::DELETE_) {
                if (_del_cb) _del_cb(ev.prev_kv().key(), ev.prev_kv().as_string());
                LOG_DEBUG("下线服务: {}-{}", ev.prev_kv().key(), ev.prev_kv().as_string());
            }
        }
    } 
private:
    NotifyCallback _put_cb;
    NotifyCallback _del_cb;
    std::shared_ptr<etcd::Client> _client;
    std::shared_ptr<etcd::Watcher> _watcher;
};